To determine the proportion of tuberculosis cases in families of an immigrant population, we explored some social, economic, and demographic variables to help is understand this phenomenon. We conducted a population-based crosssectional study between August and September, 2004 in Parcona district, province and department of Ica, Peru. The prevalence of families with cases of tuberculosis in the district of Parcona was 4.6%, and this was higher in poor families, overcrowded households and lifetime migrant families. In conclusion, this study shows that migrant populations are an important vulnerable group not only for TB infection but also for other infectious diseases in our country. further similar studies in other regions should be carried out to address this subject.